In City of Scranton v. E.B. Jermyn Lodge No. 2, 903 A.2d 129 (Pa. Cmwlth. 2006), the Supreme Court held that under the essence test, courts could, based on public policy considerations, reverse an arbitrator acting under Act 195 to award punitive damages, that decision is not applicable here because in an arbitration award involving Act 111 bargaining units, the narrow certiorari test, not the essence test, is used to review those awards. This test is much more circumscribed than the essence test. As the Supreme Court has instructed, what is in excess of the arbitrator's powers under that test is not whether the decision is unwise, manifestly unreasonable, burdens the taxpayer, is against public policy or is an error of law; an arbitrator only exceeds his power if he mandates that an illegal act be carried out or requires a public employer to do that which the employer could not do voluntarily. City of Scranton, 903 A.2d at 134-35.